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Diffstat (limited to '')
| -rw-r--r-- | src/libknot/xdp/tcp_iobuf.h | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/src/libknot/xdp/tcp_iobuf.h b/src/libknot/xdp/tcp_iobuf.h new file mode 100644 index 0000000..5a076e6 --- /dev/null +++ b/src/libknot/xdp/tcp_iobuf.h @@ -0,0 +1,129 @@ +/* Copyright (C) 2023 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +/*! + * \file + * + * \brief TCP buffer helpers. + * + * \addtogroup xdp + * @{ + */ + +#pragma once + +#include <stdbool.h> +#include <stddef.h> +#include <stdint.h> +#include <sys/uio.h> + +typedef struct knot_tcp_outbuf { + struct knot_tcp_outbuf *next; + uint32_t len; + uint32_t seqno; + bool sent; + uint8_t bytes[]; +} knot_tcp_outbuf_t; + +typedef enum { + KNOT_SWEEP_CTR_TIMEOUT = 0, + KNOT_SWEEP_CTR_LIMIT_CONN = 1, + KNOT_SWEEP_CTR_LIMIT_IBUF = 2, + KNOT_SWEEP_CTR_LIMIT_OBUF = 3, + KNOT_SWEEP_CTR_TIMEOUT_RST = 4, +} knot_sweep_counter_t; + +typedef struct knot_sweep_stats { + uint64_t last_log; // in seconds + uint32_t total; + uint32_t counters[5]; +} knot_sweep_stats_t; + +typedef struct knot_tcp_inbufs_upd_res { + size_t n_inbufs; + struct knot_tcp_inbufs_upd_res *next; + struct iovec inbufs[]; +} knot_tcp_inbufs_upd_res_t; + +inline static void knot_sweep_stats_incr(knot_sweep_stats_t *stats, knot_sweep_counter_t counter) +{ + (stats->counters[counter])++; + (stats->total)++; +} + +inline static void knot_sweep_stats_reset(knot_sweep_stats_t *stats) +{ + memset(stats, 0, sizeof(*stats)); +} + +uint64_t buffer_alloc_size(uint64_t buffer_len); + +/*! + * \brief Handle DNS-over-TCP payloads in buffer and message. + * + * \param buffer In/out: persistent buffer to store incomplete DNS payloads between receiving packets. + * \param data In: momental DNS payloads in incoming packet. + * \param alloc_bufs In: allocate extra buffers and always copy data instead of pointing inside recvd data. + * \param result Out: list of incoming DNS messages. + * \param buffers_total In/Out: total size of buffers (will be increased or decreased). + * + * \return KNOT_EOK, KNOT_ENOMEM + */ +int knot_tcp_inbufs_upd(struct iovec *buffer, struct iovec data, bool alloc_bufs, + knot_tcp_inbufs_upd_res_t **result, size_t *buffers_total); + +/*! + * \brief Add payload to be sent by TCP, to output buffers. + * + * \param bufs Output buffers to be updated. + * \param data Payload to be sent. + * \param len Payload length. + * \param ignore_lastbyte Evil mode: drop last byte of the payload. + * \param mss Connection outgoing MSS. + * \param outbufs_total In/out: total outbuf statistic to be updated. + * + * \return KNOT_E* + */ +int knot_tcp_outbufs_add(knot_tcp_outbuf_t **bufs, uint8_t *data, size_t len, + bool ignore_lastbyte, uint32_t mss, size_t *outbufs_total); + +/*! + * \brief Remove+free acked data from output buffers. + * + * \param bufs Output buffers to be updated. + * \param ackno Ackno of received ACK. + * \param outbufs_total In/out: total outbuf statistic to be updated. + */ +void knot_tcp_outbufs_ack(knot_tcp_outbuf_t **bufs, uint32_t ackno, size_t *outbufs_total); + +/*! + * \brief Prepare output buffers to be sent now. + * + * \param bufs Output buffers to be updated. + * \param window_size Connection outgoing window size. + * \param resend Send also possibly already sent data. + * \param send_start Out: first output buffer to be sent. + * \param send_count Out: number of output buffers to be sent. + */ +void knot_tcp_outbufs_can_send(knot_tcp_outbuf_t *bufs, ssize_t window_size, bool resend, + knot_tcp_outbuf_t **send_start, size_t *send_count); + +/*! + * \brief Compute allocated size of output buffers. + */ +size_t knot_tcp_outbufs_usage(knot_tcp_outbuf_t *bufs); + +/*! @} */ |